1. Field of the Invention
The present invention relates generally to cheese making. In particular, the present invention is an improved apparatus and method for production of large size blocks of natural cheese.
2. Description of the Prior Art
Natural cheese is generally manufactured by coagulating or curdling milk and cooking the resulting curd. The whey is drained from the curd, and the curd is collected and compressed. Further whey removal is achieved during the compressing stage. The compressed curd is then cured to provide the desired flavor, aroma and texture.
It has become very desirable to produce large rectangular blocks of natural cheese which may weigh as much as six to seven hundred pounds. These large blocks are subsequently subdivided into smaller consumer size blocks and packaged. The production of large blocks and later subdivision into smaller blocks results in less waste during the cheese manufacturing process, and is well adapted to large scale production.
In producing large blocks of cheese, it is necessary to maintain moisture content uniformly throughout the block. This requires draining of the whey from the curd during the compression of the curd.
One method which has been proposed for whey removal during the manufacture of large size blocks of cheese is described in U.S. Pat. Nos. 3,969,995 and 4,049,838 by Krueger and Leitner. In these patents, an open top container has a removable bottom with V shaped blades extending upward. The curd is filled into the container and a top plate having similar V shaped blades is pressed downward to compress the curd. The V shaped blades attached to both top and bottom plates are perforated to permit drainage of whey. The draining is achieved by turning the container with the blades inserted by ninety degrees and holding the container in this position for a period of time until a sufficient amount of the whey has been drained. The container is then returned to its original position, and the top plate and top blades are removed. A drain plate and tray assembly are then placed on the top surface of the cheese, and the entire container is inverted. The bottom V shaped blades, which are now at the top of the container, are then removed. The curd is then subjected to pressure and vacuum to cause knitting together of the portions of the curd which have been separated by the V shaped blades.
The method proposed in the Krueger and Leitner patents has several important disadvantages. First, it has been discovered that the compressed curd in the center section between the V shaped blades tends to pull out each time a set of blades is removed. The chunk of curd must be placed back into the container by hand, which is messy, inconvenient, and generally undesirable. Second, the method of the Krueger and Leitner patents requires a substantial capital investment for two sets of blades per container, for blade insertion apparatus, and for draining and inverting apparatus. Third, the Krueger and Leitner method requires draining for a substantial period of time with the container turned by ninety degrees.
The removal of whey from cheese curd during the production of natural cheese by means of perforated members has been known for many years. For example, U.S. Pat. No. 1,418,242 by Fieldman, U.S. Pat. No. 3,891,783 by Robertson and Bysouth, and U.S. Pat. No. 4,018,145 by Hensel all describe draining of whey from cheese curd by use of perforated members of various forms.